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A method for measuring the forces acting on a tree trunk using strain gauges
The wind force acted on a tree constantly changes in magnitude, direction, and distribution. We developed a method to measure simultaneously the amount of force (F), centroid of the distributed force (C), and direction of force (D) on a tree trunk using four strain gauges. F and C were estimated fro...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7810299/ https://www.ncbi.nlm.nih.gov/pubmed/33449960 http://dx.doi.org/10.1371/journal.pone.0245631 |
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author | Miyashita, Ayana Suzuki, Satoru |
author_facet | Miyashita, Ayana Suzuki, Satoru |
author_sort | Miyashita, Ayana |
collection | PubMed |
description | The wind force acted on a tree constantly changes in magnitude, direction, and distribution. We developed a method to measure simultaneously the amount of force (F), centroid of the distributed force (C), and direction of force (D) on a tree trunk using four strain gauges. F and C were estimated from the difference in the bending moments at two different positions along the long axis of the stem. D was estimated using the difference in the sensor outputs at two different radial positions at the same height. In principle, the two strain gauges should be oriented precisely 90° apart; however, this is unrealistic on an actual tree trunk. To calculate D, we developed a new method to detect the radial position and modulus of elasticity of each strain gauge after attaching it. We conducted three types of experiment. First, we loaded a wood pole with weights arranged in 11 patterns to test the accuracies of F and C for a distributed load. Next, we applied tensile forces to the wood pole and an evergreen conifer sapling from eight directions to test the accuracy of D, F, and C. On average, estimation errors were < 2% for both the distributed load and circumferential tensile load. Our method can estimate F, C, and D precisely, even if the wood is uneven and the strain gauges are not aligned. This is a great advantage for field wind force measurements. |
format | Online Article Text |
id | pubmed-7810299 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-78102992021-01-27 A method for measuring the forces acting on a tree trunk using strain gauges Miyashita, Ayana Suzuki, Satoru PLoS One Research Article The wind force acted on a tree constantly changes in magnitude, direction, and distribution. We developed a method to measure simultaneously the amount of force (F), centroid of the distributed force (C), and direction of force (D) on a tree trunk using four strain gauges. F and C were estimated from the difference in the bending moments at two different positions along the long axis of the stem. D was estimated using the difference in the sensor outputs at two different radial positions at the same height. In principle, the two strain gauges should be oriented precisely 90° apart; however, this is unrealistic on an actual tree trunk. To calculate D, we developed a new method to detect the radial position and modulus of elasticity of each strain gauge after attaching it. We conducted three types of experiment. First, we loaded a wood pole with weights arranged in 11 patterns to test the accuracies of F and C for a distributed load. Next, we applied tensile forces to the wood pole and an evergreen conifer sapling from eight directions to test the accuracy of D, F, and C. On average, estimation errors were < 2% for both the distributed load and circumferential tensile load. Our method can estimate F, C, and D precisely, even if the wood is uneven and the strain gauges are not aligned. This is a great advantage for field wind force measurements. Public Library of Science 2021-01-15 /pmc/articles/PMC7810299/ /pubmed/33449960 http://dx.doi.org/10.1371/journal.pone.0245631 Text en © 2021 Miyashita, Suzuki http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Article Miyashita, Ayana Suzuki, Satoru A method for measuring the forces acting on a tree trunk using strain gauges |
title | A method for measuring the forces acting on a tree trunk using strain gauges |
title_full | A method for measuring the forces acting on a tree trunk using strain gauges |
title_fullStr | A method for measuring the forces acting on a tree trunk using strain gauges |
title_full_unstemmed | A method for measuring the forces acting on a tree trunk using strain gauges |
title_short | A method for measuring the forces acting on a tree trunk using strain gauges |
title_sort | method for measuring the forces acting on a tree trunk using strain gauges |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7810299/ https://www.ncbi.nlm.nih.gov/pubmed/33449960 http://dx.doi.org/10.1371/journal.pone.0245631 |
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